数值模拟填料含量对Cu/PTFE复合材料摩擦性能的影响

为了探讨填料含量对Cu/聚四氟乙烯(PTFE)复合材料摩擦磨损的影响,运用二维颗粒流程序(PFC2D)对PTFE基复合材料在不同含量的Cu颗粒填充条件下与45#钢的摩擦磨损过程进行数值模拟分析,主要研究了Cu/PTFE复合材料的摩擦转移及磨损问题。模拟结果表明:Cu/PTFE复合材料与45#钢组成摩擦副时,会在45#钢表面形成一层转移颗粒层,转移颗粒层的形成能够有效地降低PTFE基复合材料的磨损。Cu颗粒的添加一方面可以通过自身转移的"钉扎"作用促进转移颗粒层的形成,另一方面由于提高了复合材料的整体强度,又对转移颗粒层的形成产生了一定的抑制作用。所以添加适量的Cu有利于转移颗粒层的形成,但Cu含量过高时其作用又会降低。Cu颗粒的加入降低了PTFE基复合材料的磨损量,且随着Cu含量的增加减磨效果增强。在Cu颗粒的质量分数为50%时,PTFE基复合材料的磨损颗粒数较纯PTFE的减少了近一半。

Numerical simulation of influence of filler content on tribological properties of Cu/PTFE composites

In order to investigate the influence of filler content on the tribological properties of Cu/polytetrafluoroethene (PTFE) composites, the Particle Flow Code in 2 Dimensions (PFC2D) was employed to simulate and analysis the processes of the friction and wear of PTFE-based composites with different Cu contents sliding against 45^# steel. The friction transfer and wear of Cu/PTFE composites were mainly studied. The simulation results show that the transferred particle layer is formed on the surface of 45^# steel when Cu/PTFE composites form friction pair with 45^# steel. The wear of PTFE-based composites can be reduced effectively by the formation of transferred particle layer. On one hand, the addition of Cu particles can promote the formation of transferred particle layer by "pinning" effect of self-transition. On the other hand, due to the improvement of composite integrated strength, the addition of Cu particles produces an inhibition to the formation of transferred particle layer. Therefore, the moderate addition of Cu is beneficial to the formation of transferred particle layer. However, this effect will be reduced when the content of Cu is too high. Meanwhile, the wear of PTFE-based composites is reduced effectively due to the addition of Cu particles, and antifriction effect becomes better along with the increasing of Cu content. When the mass fraction of Cu particles is 50%, the number of the wear particles of PTFE-based composites is decreased to nearly half of the pure PTFE.